Preparation dinitrotoluenes

If pure isomers are required, the ortho and meta compounds can be prepared by indirect methods. o-Nitrotoluene can be obtained by treating 2,4-dinitrotoluene with ammonium sulfide followed by diazotization and boiling with ethanol. / -Nitrotoluene can be prepared from -toluidine by acetylation, nitration deacetylation, diazotization, and boiling with ethanol. A fairly pure -nitrotoluene, which has been isolated from the isomeric mixture, can be purified further by repeated crystallization. 

Dinitrotoluene can be prepared by the nitration of -nitrotoluene with yields of ca 96% or it can be obtained from the direct nitration of toluene. 

Nitrotoluene had been distilled under reduced pressure. The residue of the distillation detonated eight hours after its end. Amongst the possible causes mentioned was ttie accidental presence of a base in the medium. Another cause could have been the presence of a quantity of 2,4-dinitrotoluene (byproduct of the preparation reaction of the distilled compound) that was larger than thought. 

More complex explosives incorporating amino groups have been prepared from the reaction of polynitroarylene halides with amine nucleophiles. Agrawal and co-workers have synthesized PADNT (107) from the reaction of 4-amino-2,6-dinitrotoluene (46) with picryl chloride (87) in methanol 4-amino-2,6-dinitrotoluene is synthesized from the reduction of... 

Amino -2,6 -dinitrotoluene Is of interest as the intermediate for one procedure for preparing the thennally-stable, insensitive expl 2,4,6-triaminotrinitrobenzene (TATB) (Ref 119). Tri-nitrophloroglucinol (TNPG, see Vol 8, P248-R), the metallic salts of which have been considered as expl initiators, can also be made from It (Ref y 4). The reactions are ... 

Dinitrotoluene, prepared by nitrating p-nitrotoluene, and free from m-nitrotoluene, should not melt below 64.5°C. It should contain not less than 96% of 2,4-dinitrotoluene.. 

The thickness of the imprinted polymer shell can be also tuned in the range 10—40 nm by changing the relative amounts of functionalised silica nanoparticles and polymer shell precursors. The resulting core-shell particles exhibit enhanced capacity of rebinding the TNT template over 2,4-dinitrotoluene in comparison to particles prepared by precipitation polymerisation. Nevertheless, this strategy, although leading to impressive results, cannot be easily applied to other templates and monomers. 

Stock solutions (1000 mg/L in acetonitrile) of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), 2,4-dinitrotoluene (2,4-DNT), and 4-amino-2,6-dinitrotoluene (4-Am-2,6-DNT) (Supelco). Sodium dodecyl sulfate (SDS) and sodium borate 10-hydrate. Standard solutions of the various explosives should be prepared daily (using the proper safety precautions) in an SDS-containing electrophoresis buffer. Platinum and silver wires, 0.1mm diameter. 

Thus the authors prepared a- nitronaphthalene from naphthalene with the yield of 80% by warming I with naphthalene. In a similar way toluene was nitrated at 80°C to 2,4-dinitrotoluene (yield 65%). By warming chloroform with I at 40-50°C chloropicrine resulted with the yield of ca. 30%. 

Dinitrotoluene (2,4-) was first obtained by Beilstein andKuhlberg [21] in 1870. However, it may be that dinitrobenzene , m.p. 71°C obtained in 1841 by St. Claire Deville [25] by the nitration of nitrobenzene prepared from light oil, was in fact dinitrotoluene. As Rosensriel [26] found in 1872 p- nitrotoluene yields only one product of dinitration, viz. the 2,4-isomer, while o- nitrotoluene gives in addition another isomer, the structure of which he did not determine. 

Dinitrotoluene, difficult to obtain by direct nitration, may be prepared in the following way ... 

The compound is prepared by the direct nitration of oxanilide (Mixter and Walther [40]). Domanski and Mieszkis [41] investigated the explosive properties of hexanitro-oxanilide and found the following values for the rate of detonation of the pressed product mixed with 2% of dinitrotoluene ... 

Dinitrobenzoic acid has been prepared by nitration of o-nitrobenzoic acid and fractional crystallization of the acids as the barium salts 1 and by oxidation of 2,5-dinitrotoluene.2... 

Summary A-NPNT is prepared in a three step process starting with the well know high explosive, TNT. TNT is reduced to 4-amino-2,6-dinitrotoluene with hydrogen sulfide gas and ammonia solution. The reduction product is then converted to 4-... 

Analogous Sulfonations. Exactly the same method can be used for sulfonating p-nitrochlorobenzene, p-nitrotoluene, o-m trochlorobenzene, chlorobenzene, and many other compounds. On the other hand, it is usually not possible to sulfonate dinitaro compounds in this way. Dinitrochlorobenzene and dinitrotoluene are decomposed explosively by treatment with fuming sulfuric acid. If dinitrochloro-benzenesulfoitic acid is to be prepared, for example, one starts with p-nitrochloro-benzene/ This is sulfonated, as described previously, and the sulfonic acid is converted to dinitrochlorobenzenesulfonic acid by treatment with mixed acid (50 50 sulfuric and nitric acids) at low temperatures. This product yields, on replacement of the chlorine by —OH and partial reduction, 4-nitro-2-aminophenol-6-sulfonic acid (nitro acid III), which is used in preparing chrome dyes. 

Cahours also prepared a dinitrotoluene, but unfortunately he did not leave any data as to which of the isomers he obtained. 

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